I've seen grommets used in canvas for that very reason. I've never
seen them used in awnings, but why not? Cheap brass grommets from a
hardware or home supply store work. if you want nickel plated
grommets, you can get them at a marine canvas supply house, such as
sailrite.com, but nickel plated grommets are "star" grommets (star
grommets also come in brass), which are much stronger AND require
special (and expensive) dies to set them. In an awning you won't need
the extra strength. I'd go with the hardware store grommets.